MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
Contact: Martha J. Heil (818) 354-0850
FOR IMMEDIATE RELEASE August 6, 2002
Stardust Spacecraft Reaches For Cosmic Dust
NASA's Stardust spacecraft, on a mission to collect and return
the first samples from a comet, began yesterday to collect tiny
specks of solid matter, called interstellar dust grains, that
permeate the galaxy.
"If you look at the Milky Way on a dark night you may see a
black band stretching along the center. The band is interstellar
dust blocking the light from distant stars. These are the
particles that Stardust will be collecting," said Dr. Don Brownlee,
an astronomy professor at the University of Washington, Seattle,
and the principal investigator of the Stardust mission.
This dust, passing through the solar system like a wind, is
made of particles smaller than one-hundredth the width of a human
hair. The particles are made of varying amounts of most of the
elements in the periodic table. The Stardust mission will use its
special formulation of aerogel, the world's lightest solid, to try
to capture these small solid particles as the spacecraft travels in
the same direction as the dust stream until December 9, 2002.
"Stardust's tennis-racket-shaped particle collector has
shoulder and wrist joints that will point one side of the aerogel
collector material into the dust stream to collect interstellar
dust," said Tom Duxbury, the project's manager at NASA's Jet
Propulsion Laboratory, Pasadena, Calif. "When Stardust encounters
comet Wild 2 in early 2004, the reverse side of the collector will
trap particles from the gas and dust escaping from the inside of the
comet. When the dust samples return to Earth in 2006, we will
extract and analyze the particles,"
The Stardust mission collects both ancient and young dust.
Comets are made of interstellar particles that clumped together
with ices more than 4.5 billion years ago. When the spacecraft
flies past comet Wild 2, it will attempt to collect ancient dust
samples stored for billions of years in, effectively, a deep
The mission began yesterday collecting a younger type of
stardust: the free-flowing interstellar dust that was produced by
the current generation of stars. Comparing the ancient and newer
types of dust may provide clues to the evolutionary changes in the
galaxy and the composition of the early galaxy. This is the second
and final time Stardust will collect these dust particles. It
previously collected samples during a six-week period in 2000.
Comet Wild 2 is a particularly good example of preserved
interstellar dust because its path through space brings it no
closer to the Sun than Mars' orbit, about 228 million kilometers
(about 141 million miles) from the Sun. Before 1974, the closest
Wild 2 came to the Sun was Jupiter, Brownlee said.
NASA's Galileo and Ulysses spacecraft both detected a
stream of dust particles flowing between stars and into the
solar system. The particles did not come from the Sun, but from
another direction that showed their origin was outside the solar
Interstellar dust may have played a role in bringing the
building blocks of life -- carbon and other organic materials --
to the young Earth. Similarly, comet impacts may have also brought
these elements to Earth. Brownlee expects to find a lot of carbon
in the interstellar dust particles. "When Earth-like planets form,
comets and interstellar grains may bring carbon and organic
material," he said.
The interstellar dust stream differs from the solar wind in
that the solar wind is made of individual atoms, while the
interstellar dust is made of small particles of rocks with
Stardust, a part of NASA's Discovery Program of low-cost,
highly focused science missions, was built by Lockheed Martin
Astronautics and Operations, Denver, Colo. and is managed by JPL
for NASA's Office of Space Science, Washington, D.C. JPL is a
division of the California Institute of Technology in Pasadena.
More information on the Stardust mission is available at